Art of curved and tapered tank manufacture



Nov. 14, 1944. A. F. MEYER 6 ART OF CURVED AND TAPERED TANK MANUFACTURE Filed June 26, 1942 3 Sheets-Sheet 1 ATTORNEYS Nov. 14, 1944. A. F. MEYER 2,362,657

ART OF CURVEDv AND TAPERED TANK MANUFACTURE Fi1ed M26, 1942] s Sheets-Sheet 2 ATTORNEY.

A. F. MEYER Nov. 14, 1944.

ART OF QURVEDIND TAPERED TANK MANUFACTURE Filed June 26. 1942 Sheets-Sheet 3 INVENTOR. Md. 5. 777701 memZZ #mwz ATTO RNEY.

Patented Nov. 14, 1944 ART OF CURVED AND TAPERED TANK MANUFACTURE Arnold F. Meyer, Pewaukee, Wis., assignor to The Heil 00., Milwaukee, Wis., a corporation of Wisconsin Application'June 26, 1942, Serial No. 448,657

2 Claims. (Cl. 113120) This invention relates to improvements in the art of curved and tapered tank manufacture.

In my co-pending application No. 448,656, filed on even date herewith, I have described a tapered transportable tank for incorporation in a wheeled vehicle, such as a semi-trailer. The tank, disclosed in said co-pending application, and also forming the subject of this application, has decided advantages over the conventional trailer tank of uniform cross-sectional area or a trailer tank of the so-called drop-frame type. It is characterized by a tapered formation, increasing in cross-sectional area from one end to the other, with thetank being of substantially ovate form in cross-section, and fabricated from a pair of complementary longitudinally extending plates, each of substantially semi-oval form with adjacent over-lapping edges of the complementary plates being secured together along longitudinal lines on opposite sides of the tank. There are, however, certain problems involved in the economical and expeditious fabrication of a tank of the class above described, and a primary object of the present invention is the provision of a method of forming and fabricating curved and tapered tanks, which method is practical, economical, expeditious, and well suited for commercial and large scale operations.

In the transportable tank under consideration the longitudinal median of the top of the tank is substantially horizontal, or at the same elevation from the ground throughout, while the longitudinal median of the bottom of the tank is gradually and uniformly'downwardly inclined from front to rear. The curved top section of the tank may be formed from a composite sheet of rectangular formation which is uniformly rolled to the correct curvature. However, to provide for the tapering shape of the tank the curved lower section thereof, which is preferably a composite sheet of gradually increasing width toward one end, presents complications to'avoid complicated rolling operations wherein the axis of the roller would ordinarily have to be changed continuously with respect to its angle with the center line of the sheet.

It is, therefore, a more specific object of the invention to provide a tapered bottom section forming sheet for a tank and method of rolling the same into curved form which eliminates the difiiculty above-mentioned and wherein said sheet posite side edges of the sheet to leave straight and un'rolled transition sections of tapered formation, the latter when joined to the side edges of the curved top section of the tank compensating for the gradual change in cross-sectional area from the front to the rear of the tank.

A further object of the invention is to provide a method of forming a curved and tapered tank through the union of complementary curved top and bottom tank sections, the former being of uniform cross-sectional area throughout, and the latter being of gradually increasing cross-sectional area from front to rear.

A further object of the invention is to provide a curved bottom forming tank section whose major intermediate portion is rectangular and is curved in a uniform arc, and whose side edge portions are of triangular formation and plane.

With the above and other objects in view, the invention consists of the improved art of curved and tapered tank manufacture, and all of the steps, parts, and combinations incident thereto, as set forth in the claims, and all equivalents thereof.

In the accompanying drawings in which the same reference characters indicate the same parts in all of the views:

Fig. 1 is a side view of an improved curved and tapered trailer tank, constructed according to the present invention, with the outer casing of the tank and the axle shown in section;

Fig. 2 is a top View of the tank with a portion of the outer casing, broken away and in section;

Fig. 3 is a transverse vertical sectional View taken on line 3-3 of Fig. 1;

Fig. 4 is a transverse vertical sectional view taken on line 4-4 of Fig. 1;

Fig. 5 is a plan view of a composite blank used for forming the bottom section of the tank;

Fig. 6 1s a side view illustrating the blank of Fig. 5 after it has been rolled into curved, semiovate form, the relationship of an upper'tank section to said bottom section being shown in dotted lines; and r Fig. 7 is a rear end view of the curved bottom section of Fig. 6 with'a dotted line showing ,of

the curved top section associated therewith.

A completed curved and tapered tank embodied in a vehicle of the semi-trailer type is shown in Figs. 1 to 4 inclusive. Generally speaking there is an inner metallic shell formed of complementary upper and lower sections l0 and II respectively, each curved into substantially semiovate form and having its edges in overlapping relationship and welded to provide longitudinal side seams l2. The shell is of gradually increasing cross-sectional area from front to rear and is rranged to provide a gradually and uniformly rearwardly sloping bottom l3. The top of the shell is, however, horizontal and of uniform height from the ground throughout. Both ends of the shelLareclosed by suitable .welded in heads l4 and [5. The interior of the shellmay be subdivided by a suitably positioned partition 16.

The innershell is enclosed by an outer sheetmetal casing I! which is shaped similarly to the Hi, and engage and support theinner shell 11!.

At the forward end of the tank 'the supporting "feet 21 extend upwardly'from a 'fift'h' wheel plate 22 and similarly project through openings in the outer casing lI'an'd engage-and support the in- .ner shell Ill.

The vehicular mounting for the rear and enlarged end of the tank assemblage comprises a set of rear supporting' w'heel s23 rotatably mounted upon a transverse reartrailer'axle'u which is associated with leaf springs '25, the latter being pivotally attached to the transverse beams.

The forward end-of the semi-trailer vehicular structure is -a'daptedto be supported by the rear end of a'tractor or other propelling'vehicle. As shown in Fig. l, thetank carried fifth wheel plate 22 cooperates with the tractor carried complementary fifth wheell'fiywith the result that the front end portion of the tank 'vehicle is turnablethroughthe 'engagementsof'the cooperating fifth wheel members 22 and 26 and a king'pin 21.

It will thus be seen that in the-vehicular tank the .rear end portion of the tank is resiliently supported on trailer wheels at "a relatively low i elevation, close to the spring and axle assembly. The forward end portion of the tank, which is of reduced cross-sectional area, is supported on 'the'tractor' a't a propen elevation'somewhat higher than the elevation of the-rear of the tank. The

vehicular ;tank,'overall, is relatively low and has a lowcenter of'gravity. *It'is also to be observed thatthe bottom 'of the commodity carrying tank is uniformly downwardly inclined from front to rear so that gravity will cause the contents to flow rearwardly for discharge 'througha rear dispensing valve 28. Y a

As previously mentioned, the "curved and tapered tank shell is fabricated from .a pair of metal sheets Hland'l l respectively. The sheet ill) to formthe curved top section of the tank shell is rectangular, while the sheet 11 (see Fig.

5) to form the curved bottomsection of the tank shell .of increasing cross-sectional :area, is substantially quadrilateral, increasing in widthfrom gether. I

With the present improved method the shaping of the top forming sheet I0 presents no unusual problems.

A roller is used to curve -the-- being made up of smaller sections "Welded ltosheet in a desired, uniform arc, it being noted that extreme side edges of the sheet are left plane for convenience in lapping the same with the side edges of the bottom forming sheet H.

Referring now more specifically to Fig. 5, which depicts the bottom forming blank, it will be noted that the longitudinal center .line thereof is indicated by the .character va. :Equidistantfrom the center line a are indicated lines '27 and c which are both parallel to the center line. At the reduced end of the sheet I I the lines b and 0 merge with the extremities of the rectilineal outer side edges of said sheet, designated (1 and e, respectively. Hence the portion of the sheet ll between the lines D, d and the'wide end of the sheet is of triangular formation, as is the narrow area bounded by the lines 0, e and the wide end of 'the sheet. The major portion of the sheet between the lines b and c is substantially rectangular. The latter portion of the sheet may be readily curved into a-desirediarcby 'a roller op- I crating on the sheet substantially between the lines I) and c. It is highly important to observe that the :axis of the roller :may be maintained parallel to "the center .line a of the sheet, so the rolling operation, carried out in his manner is very simple and expeditious. Asa practical matter the major rolling roperations stop a trifle short of the lines band 0, and that portion of the sheet between points 7 and g'in Fig. 7 is curved in a uniform-arc whose center is at point h. Between points f'andc, and g and 'b the radius of curvature is increased so that the plane surfaced triangular areas 3B and 34 :project upwardly perpendicularly.

The enclosedtankbody or shell is-composed 0f the curved top and bottom forming plates 1'0 and M respectively, the former being :of uniform breadth throughout'and the latter gradually'increasing 'in'breadth from "front-to rear Portions of the plane side 'ed-ges30 'and 3-l of the sheet H are arranged so as 'to overlap the depending plane side edgesof the "top shee't l0. 'I'he'sheets :are connected in this relationship by the side longitudinal lines-of weld I 2'previously mentioned. The ends of the shell are then closed by the weld- 'ed in end heads 14 and 15 also previously mentioned.

In the exemplification illustrated the inner shell is surrounded by an outer sheet metal casing H. This casing is similar in shape to "the inner shell and is formed of complementary curved top and bottom plates rolled into form in. a manner similar to that employed in connection with the sheets of the'shell'and similarly connected together.

While it is preferable to form the sheets of the shell and casing by sections welded together with the rolling operations being performed on the large composite sheets, it is possible to first 'roll each section of a sheet, "and subsequently connect the small sections to form the large composite, curved sheets.

'It might ordinarily be supposed that in formsion of the triangular transition areas at the sides thereof, which are plane, the rolling of the major portion of the plate or sheet is simplified.

As will be noted from Figs. 1 and 6, the lines of connection between the top and bottom sheets at opposite sides of the shell are parallel to the longitudinal median of the top of the shell, instead of biased or inclined downwardly. The longitudinal median of the bottom of the shell is inclined downwardly toward the rear of the shell. This relationship is preserved when the tank is mounted on wheels, as in Fig. 1, and is of considerable advantage. The top of the tank remains horizontal and at a uniform elevation from the ground. The bottom portion of the rear of the tank may be supported at a relatively low elevation, while the bottom portion of the front of the tank is somewhat higher for proper engagement with a tractor fifth-wheel mechanism.

Various changes and modifications may be made in the tank elements and the method of forming curved and tapered tanks without. departing from the spirit of the invention, and all such changes are contemplated as may come within the scope of the claims.

What is claimed as the invention is:

r 1. The method of forming a transportation tank shell having an interior chamber which is curved in cross section and which is of substantially the same horizontal width throughout its length and of progressively less depth from one end to the other comprising providing a flat, rectangular first plate, rolling said plate throughout its length in a transverse are so that said plate when bent has substantially the same cross section throughout the major portion of its length, providing a flat quadrilateral plate of gradually increasing breadth from one end to the other, rolling the latter plate throughout its length in a transverse are which is substantially as long as and has substantially the same radius as the arc of rolling of said first plate, the axis of curvature of said are of the second plate being parallel to the longitudinal median of said secend plate, terminating the latter rolling operations in straight lines parallel to said median and removed from both side edges of the plate to leave narrow tapered outer edge areas which are flat, projecting said areas substantially perpendicularly toward the concavity while maintaining said areas in substantially flat condition, and assembling both plates in enclosure forming relationship by joinin both side edges of the first plate with the respective side edges of the fiat tapered areas of the second plate to provide a shell having a progressively decreasing depth caused by said flat taperedareas.

2. The method of forming a transportation tank shell having an interior chamber which is curved in cross section and which is of substantially the same horizontal width throughout its lengthand of progressively less depth from one end to the other comprising providing a flat, rectangular first plate, rolling said plate throughout its length in a transverse arc so that said plate when bent has substantially the same cross section throughout the major portion of its length, providing a flat quadrilateral plate of gradually increasing breadth from one end to the other, rolling the latter plate throughout its length in a transverse arc which has substantially the same radius as the arc of rolling of said first plate by means of a roller operating transversely of said plate with the axis of the roller at all times maintained parallel to the longitudinal median of said plate, the axis of curvature of the arc of the second plate being parallel to the longitudinal median of said second plate, terminating the latter rolling operations in straight lines parallel to said median and removed inwardly irom both side edges of the plate to leave narrow tapered outer edge areas which are flat, projecting said areas substantially perpendicularly relative to the concavity while maintaining said areas in substantially plane condition, and assembling both plates in enclosure forming relationship by joining both side edges of the first plate with the respective side edges of the flat tapered areas of the second plate to provide a shell having a progressively decreasing depth caused by said plane tapered areas.

ARNOLD F. MEYER. 

